Hepatic drug metabolism is impaired in patients with liver disease. Clearance rates of drugs can reflect residual liver function & followed over time, show progressive liver disease & be of value in timing liver transplantation. In this project, clearance of substances metabolized in the liver will be compared in patients with cirrhosis & normals to determine if these are useful for assessing degrees of liver impairment. Substances studied will include coumarin, caffeine, & methacetin, which are given by mouth, & endogenous cortisol & bile acids.